Hi I had a major problem with algae so I hunted about and purchased a sucking loach, within a few days he (I think) had got to work and cleared the lot.
The beauty is that he is left alone by the cichlids, and if he is bothered he can more than look after himself, and frequently chases them back if the others hound him.
It is the ultimate green solution, no chemicals, no stressing the fish by moving the rock about.
hope this helps.